change of variables



On 10/23/07, apeditedirra unasaltao <pi_e_dra at yahoo.es> wrote:
>
> Maxima knows how to integrate this:
> integrate(u(x)*diff(u(x),x),x);


Yes, it recognizes the case of Q*diff(Q,x) in some cases. It could certainly
recognize more.

but not this:...
>   Why this limitation?
>
> should'nt maxima try the trivial change of variables when it knows the
> answer to the new integration?
>

There is no simple answer to this.

But feel free to study the integration code in sin.lisp, sinint.lisp, etc.
to see if you can improve it.

          -s